THIRD ANNUAL REPORT 
Of T. A. Conrad, on the Palaeontological Depart- 
ment of the Survey. 
The superstructure of modern geology is based chiefly on organic 
remains, and it must be a narrow and partial view of the subject, which 
would not assign to their investigation a prominent place in a geological 
exploration, thus guarding against visionary hopes of treasure and erro- 
neous conclusions which would otherwise meet the geologist at every 
step. Fossils, indeed, in their relations to geology, may be compared 
to the balance wheel of an engine, which gives regularity and certainty 
to its motion, and they harmonize with, and shed light on the other de- 
partments of the science. The most enlightened geologists of Europe 
will bear me witness that I do not give undue importance to this fascinat- 
ing study. They have almost unanimously made mineral character in 
identifying formations, subordinate to the more intelligible record of or- 
ganic remains in whole series of rocks above the primordial system, 
and every day's observation tends to confirm the singular agreement in 
the fossil contents of equivalent strata in every region of the globe, how- 
ever diversified may be the mineral composition of the rocks. Thus, 
we are taught that the living beings of a certain era, were generally 
spread throughout the extended ocean, which pervaded the greater portion 
of the globe; the uniformity of the groups being greatest in proportion 
to the antiquity of the rocks which now hold their remains. Thus the 
identity of several ancient formations in Europe and America is clearly 
determined, and the mineral treasures are found to correspond in a re- 
markable manner, showing that the same general causes influenced the 
deposition of the rocks ovei a vastly extended area, thus giving to geo- 
logical science a more tangible character, and a firmer base than its 
most ardent admirers would a few years since have dared to hope it 
would so speedily acquire. 
